Portable greenhouse



FIG. 1 is a front, perspective view of the portable greenhouse showingmy new design;

FIG. 2 is a side, elevational view taken from the right of FIG. 1;

FIG. 3 is a front elevational view of the portable greenhouse; and

FIG. 4 is a rear elevational view of the portable greenhouse.

The ornamental design for a portable greenhouse, as shown.